#!/bin/sh
# 
# Plugin to monitor the load average on a system.
#
# Usage: Link or copy into /etc/munin/node.d/
#
# Parameters
#     env.load_warn <warning load>
#     env.load_crit <critical load>
#
# Magic markers (optional - only used by munin-config and some
# installation scripts):
#
#%# family=auto
#%# capabilities=autoconf

# If run with the "autoconf"-parameter, give our opinion on wether we
# should be run on this system or not. This is optinal, and only used by
# munin-config. In the case of this plugin, we should most probably
# always be included.

. $MUNIN_LIBDIR/plugins/plugin.sh

if [ "$1" = "autoconf" ]; then
	echo yes
	exit 0
fi

# If run with the "config"-parameter, give out information on how the
# graphs should look. 
 
if [ "$1" = "config" ]; then

	# The host name this plugin is for. (Can be overridden to have
	# one machine answer for several)

	# The title of the graph
	echo 'graph_title Load average'
	# Arguments to "rrdtool graph". In this case, tell it that the
	# lower limit of the graph is '0', and that 1k=1000 (not 1024)
	echo 'graph_args --base 1000 -l 0'
	# The Y-axis label
	echo 'graph_vlabel load'
	# We want Cur/Min/Avg/Max unscaled (i.e. 0.42 load instead of
	# 420 milliload)
	echo 'graph_scale no'
	# Graph category. Defaults to 'other'
	echo 'graph_category system'
	# The fields. "label" is used in the legend. "label" is the only
	# required subfield. 
	echo 'load.label load'
	# These two read the environment for warning values for the field
	# "load".  If "load_warning" or "warning" aren't set in the
	# environment, no warning levels are set.  Likewise for "load_critical"
	# and "critical".
	print_warning load
	print_critical load
	# This one is purely to add an explanation to the web page. The first
	# one is for the graph itself, while the second one is for the field
	# "load".
	echo 'graph_info The load average of the machine describes how many processes are in the run-queue (scheduled to run "immediately").'
	echo 'load.info Average load for the five minutes.'

	# Last, if run with the "config"-parameter, quit here (don't
	# display any data)
	exit 0
fi

# If not run with any parameters at all (or only unknown ones), do the
# real work - i.e. display the data. Almost always this will be
# "value" subfield for every data field.

echo -n "load.value "
cut -f2 -d' ' < /proc/loadavg
